Dimmer switch



FIG. 1 is a front perspective view of a dimmer switch showing our new design;

FIG. 2 is a front view thereof;

FIG. 3 is a back view thereof;

FIG. 4 is a bottom view thereof;

FIG. 5 is a top view thereof;

FIG. 6 is a right side view thereof; and,

FIG. 7 is a left side view thereof.

The environmental structure shown with broken lines in the drawings forms no part of the claimed design. 

CLAIM The ornamental design for a dimmer switch, as shown and described. 